PPI for gpio event to gpio task is not working

Question

Hi,

I just tried to toggle a led when a particular button in the evaluation board (nrf51822) is pressed, i just referred the gpiote sample code and started modifying it. Below is my code snippet, please help me to overcome this.

static void gpiote_init(void)
{
	  nrf_gpio_cfg_input(BUTTON_0, NRF_GPIO_PIN_NOPULL);
    nrf_gpiote_event_config(0,16,2);
		
	  nrf_gpio_cfg_output(18);
    nrf_gpiote_task_config(0, 18, 2, 0);
				
}

static void ppi_init(void)
{
   
    NRF_PPI->CH[0].EEP = (uint32_t)&NRF_GPIOTE->EVENTS_IN[0];
    NRF_PPI->CH[0].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[0];

    // Enable PPI channel 0
    NRF_PPI->CHEN = (PPI_CHEN_CH0_Enabled << PPI_CHEN_CH0_Pos);
}

int main(void)
{
	
	
	  gpiote_init();                 
          ppi_init();

Regards, Balaji

Ole Morten · Accepted Answer

You can't use one GPIOTE channel both for input and output, so you'll have to move one of them to use another GPIOTE channel (i.e. use another GPIOTE->CONFIG register).